Adaptive Brief Interventions for Drop-out Re-engagement. There is a critical need for psychosocial interventions to improve treatment retention in outpatient substance abuse treatment programs. We are proposing a 5-year Stage I behavioral therapy development study to: 1) prospectively evaluate risk factors for premature drop-out from outpatient treatment; 2) develop and test a manual of single session phone- and office-based interventions to re-engage these high risk patients in treatment. A prospective risk factor assessment will involve the evaluation of 300 recently admitted outpatients to identify predictors of treatment drop-out and retention over a 24-week assessment period (baseline and weeks 4, 8, 12, and 24). We hypothesize that subjects who report problems with coping, motivation, or family support will be at heightened risk for outpatient drop-out and that these will be relevant risk factors for developing strategies for re-engagement. A Stage IA treatment development phase will create and pilot test an Adaptive Brief Interventions (ABI) manual with a subsample (n=40) of risk factor assessment subjects (from first two years of the project) who drop-out within the first 12 weeks of outpatient treatment. In Stage IB, we will conduct therapist training and credentialing in ABI and test the intervention in another subsample (n=80) of risk factor assessment subjects (from the second two years of the project) with the goal of re-engaging early treatment drop-outs. This will involve a randomized clinical trial comparing routine counselor follow-up in Standard Clinic Care (SCC) versus standard care enhanced by a planned, sequence of single session phone- or office-based interventions (ABI). We hypothesize that ABI will result in better re-engagement and retention in outpatient treatment than SCC alone over the first 12 weeks of treatment and at 24-week follow-up (primary outcome). In addition, we predict better reduction in substance use, severity of psychosocial problems, increases in motivation to change behavior and receive treatment, treatment satisfaction, and use of ancillary services in ABI than SCC (secondary outcomes).